The invention relates to a method for colored patterning of a web-shaped nonwoven or a composite of a nonwoven and a fabric or knit by means of hydrodynamic needling, with the web lying on a substrate and moving-past a nozzle beam arranged crosswise to the transport direction and impacted by the water jets.
A method of this kind is known from WO 89/09850. According to this document, a colored web is guided over a plane provided with a three-dimensional pattern and impacted by water jets to produce a washed-out effect on the initially off-color inking.
A pattern without inking is possible using hydrodynamic treatment when, according to U.S. Pat. No. 4,691,417 or EP-A-0 400 349, the waterjets are directed at the web of goods such as a nonwoven through a sheet with a perforated pattern. The water jets, as viewed over their area, impact the fibers of the web of goods only partially and displace it only there to form a pattern similar to a watermark.
The goal of the invention is to find a method for achieving a colored patterning of a web of goods, in which a pattern results from hydrodynamic treatment which has the desired colors and pattern types and sizes, without having to be alert for washing-out effects.
Taking its departure from the method of the type mentioned at the outset, the invention provides as a solution to the stated goal that a nonwoven provided with one or more colors or dyed or printed is chosen as the upper layer of two layers, and this nonwoven is placed on a second nonwoven or woven or one having a different color and both layers are subjected to the water jets which displace the fibers. The colored fibers of the first layer are displaced into the second layer to produce a pattern on the underside of the second layer.
The nonwoven in the first layer can come directly in front of a card and has fine fibers of one or different colors. When these fibers are subjected to the water jets, they are moved into and through the second layer. Hence, not only the known solidification of the webs alone and with one another takes place but the fibers of the first nonwoven reach the underside of the second web of goods and produce a pattern of some type there because of their own color. This pattern can be influenced in a wide variety of different ways.
A color pattern according to the invention can also be produced by the second web being produced with dyed fibers for example instead of the dyed fibers of the first nonwoven and then for example white fibers in the first nonwoven penetrate to the back of the colored second nonwoven by the water needling and there they produce a pattern of some type on the underside. This pattern can be influenced in a wide variety of different ways as well.
To produce a pattern on the back of the second web of goods with the fibers of the first nonwoven, it is important for these fibers to be readily movable by the water jets, in other words for them to have a fine titer such as 1-6 dtex in diameter and a finite length of 20 to 100 mm. In any case, the first nonwoven is non-solidified and is a light card nonwoven. The second web, on the other hand, can also be a nonwoven but it can be pre-solidified by mechanical needling for example or it can be a weave or a knit that forces a definable direction of the fibers penetrating from the first nonwoven by its internal thread structure. This is typical of the pattern that can be produced on the underside. It is also important in this regard, from what fibers the second web is produced: Their thickness, properties, and the strength of the thread structure of the second web are important.
Quite different color patterns can be produced if a third means for steering the water jets in a desired direction is added. This means can be located in front of or between the two layers or even below the second web. If the element is located between the webs, it is obvious that it remains permanently in the total product. It is different if for example the water jets are aimed at the first nonwoven by an endless belt or drum that is permeable with a pattern that unrolls directly on the nonwoven. The partially colored fibers of the first nonwoven are partially transported through the second web so that it is only at these places that coloration of the back of the second web or patterning takes place.